Members of the British royal family make themselves available to the public through carefully choreographed royal engagements, so if you ever find yourself in the enviable position of rubbing shoulders with a royal, your own conduct should be thoughtful, as well.

INSIDER asked royal expert and commentator for CNN Victoria Arbiter how to properly greet a royal should the opportunity ever arise.

Here are four ways to make a good impression and avoid breaking royal protocol.

1/

The most important rule: don't touch them.

LeBron James forgot that you're not supposed to touch royals.
Tim Rooke/Pool/Getty Images

This is both for security reasons and out of regard for their positions.

"What you would absolutely not do is launch and give a big hug to the Queen, or try to kiss them or put your arms around them. That's a big no-no," Arbiter told INSIDER. "Really it comes down to don't touch a royal. I'm sure there's lots of security reasons associated with it, but it's just not befitting of their position."

2/

Don't call them by their first names.

That's "Your Majesty" to you.
Chris Jackson/Getty Images

Royal titles indicate an elevated level of respect, so make sure you know how to address members of the royal family correctly.

The first time you address the Queen, you call her "Your Majesty." From there on, address her as "Ma'am."

With other royals like Kate Middleton or Princess Anne, it would be "Your Royal Highness," and then "Ma'am."

3/

Don't forget to bow or curtsy.

Even members of the royal family curtsy to the Queen.
Chris Jackson/Getty Images

According to the royal family's official website, "There are no obligatory codes of behavior when meeting the Queen or a member of the Royal Family, but many people wish to observe the traditional forms."

Especially if you're not a British citizen, bowing or curtsying isn't necessary when meeting a royal. But how often do you get the chance to greet a current or future monarch the old-fashioned way?

According to Arbiter, there's also a generational difference in terms of expected royal greetings.

"Certainly with the Queen because she's the Queen and the older generation, you would most definitely want to curtsy," Arbiter said. "The younger generations are a lot more relaxed when it comes to curtsying, so it's certainly not a requirement, but it comes down to greeting someone with respect."

Members of the royal family do bow or curtsy to the queen if they're seeing her for the first time that day. And Meghan Markle's future brother and sister-in-law, Prince William and Kate Middleton, would also warrant a curtsy from her because of William's position as a future king.

You can learn more about who curtsies to whom within the royal family here.

4/

Don't ask for a selfie.

Get someone else to take the photo.
Julian Simmonds/Pool/Getty Images

Taking selfies with royals is "strongly discouraged," and often even prohibited on walkabouts, according to Arbiter.

For one thing, taking a selfie requires close proximity, which could be a security issue. But royals also prefer having personal interactions over posing for photos in a crowd. And if you grant one person a selfie, there will be hundreds more who want one, too.

If you accidentally break royal protocol in a small way, however, it's okay.

Royals have a sense of humor, too.
Niall Carson/WPA Pool/Getty Images

Don't worry — there's no royal police force that will come after you if you initiate a handshake or forget to curtsy.

After many years on the job, life as a royal can get pretty predictable. Every public outing is meticulously scheduled, and every movement is planned. So when someone slips up in a small way, it adds a bit of fun to their otherwise regimented routine.

"Sometimes, the royal family quite like it when things go wrong because it adds a bit of humor and it gives them something to enjoy and talk about," said Arbiter.